The Bath Viaduct will reopen next week, nearly a month ahead of schedule.

Traffic has been detoured through downtown Bath since October, as contractors for the Maine Department of Transportation demolished and rebuilt the highway span. The deadline to finish the $12 million project was Memorial Day, but contractor Reed & Reed was able to complete construction approximately 25 days ahead of schedule, said Department of Transportation project engineer Glenn Philbrook in a statement. The roadway is expected to open sometime before Friday, May 5.

Work will continue on surface streets and frontage roads underneath and adjacent to the viaduct after it is reopened to traffic. The final stage of the project is expected to continue through July.

The viaduct carries Route 1 over Bath. Approximately 18,000 vehicles a day travel the highway.